We viewed the slash as a brick wall due to the problem of getting the geometry from the CAD system transfered to the CAM system where this geometry could be used to drive a CNC machine.
There are many different CAD systems that have been marketed over the years, and each has it's own scheme for storing geometry. Several standard formats have been used as a common base for geometry, such as IGES and DXF with varying degrees of success.
At FlyingFoam.com, we have several problems in dealing with CAD files.
Problem #1
CNC machines don't program themselves. Some CAD system users believe that you can load a CAD file into a CNC control system, and the part will be made. Nothing could be further from the truth!
Manufacturing engineers spend many hours modifying and sometimes recreating geometry so tool paths can be created for their CNC machine. Creating tool paths, or the motion commands to drive the CNC machine, is a necessary step that can be time consuming.
Problem #2
We use TurboCAD to read your CAD file. We can read files in the following formats:
.dxf
.dwg
.tcw
The first 2 are AutoCAD files, and .tcw is TurboCAD's native file for Windows. We require that your data is in one of the above formats. We would like to be able to read your native CAD file, but we are financially unable to purchase and learn to use all of the popular CAD systems that are in use today.
Problem #3
CAD systems can be used to design objects that are impossible to make.
We use a hot wires that is driven by a CNC control. We are limited to cutting extrusions and ruled surfaces. We cannot cut complex surfaces that are defined by more than 2 curves or cross sections.
Examples of the types of surfaces and parts that are possible with our equipment are shown to the left.
Parts that are not possible are shown on the right of this column.
Our equipment is designed specifically for cutting ruled surfaces as used for Model Aircraft and UAV's. They can tilt and turn the hot wire to some rather extreme angles, but they do not have the complete freedom required to cut all ruled surface types.
Where CAD Files work well
Airfoil Definition
CAD files can be handy way to send airfoils to us. Airfoil shapes are usually defined as splines or polylines. If you are sending us a CAD file that contains airfoil shapes, please limit the shape to 200 segments or less. As few as 20 segments will accurately define most airfoil shapes. We have tools to curve fit additional points if needed.
Complex Extrustion Profiles
Complex profiles consisting of lines, circles and/or splines can easily be defined by a CAD system. You should define your profiles to the desired size and shape. We will make allowance for wire kerf and sheeting allowance if needed.
A Picture is worth a thousand words!
CAD files are a great way to describe spar shapes, tube hole locations and other features in your job. Although we may not use the geometry directly, your CAD drawing can be helpful and may be required to describe your foam parts.
In some cases, a .pdf, .jpg or other picture file may be all that is needed to describe your foam parts, and these files can be created by most CAD systems. Picture files are usually easier to transmit and read.
Send your CAD file as an Email attachment to:
bob@flyingfoam.com
Please include your address and phone number in your Email.
